The present invention relates to an electromagnetic induction heating apparatus which heats a magnetic vessel with a magnetic force that is generated by switching on the current flow in a working coil in order to cook food contained in the magnetic vessel More particularly, the present invention relates to a method for controlling the drive of an electromagnetic induction heating apparatus, that is, an electromagnetic heating cooker, which is designed to control the drive of a power transistor by commonly utilizing a time control method and a linear control method according to the power level selected by a user.
In order to control the apparatus drive, a conventional electromagnetic induction heating apparatus, a time control method varies the number of times that a power transistor is switched ON/OFF according to the power setting level, while the power control level is maintained constant on one hand. On the other hand, a linear control method varies the ON/OFF switching time of a power transistor by changing the power control level according to the power setting level.
However, in case where the former method is adopted because the power control level is constant, the ON/OFF switching time of the power transistor is constant. Thereby, a so-called "flicker effect" may be generated when the power control level is high.
On the other hand, in the case where the latter method is adopted, the above stated "flicker effect" does not occur. However, an extreme amount of noise is generated when the power control level is low since the switching frequency varies upon the change of the ON/OFF switching time of the power transistor.